Because animal fats tend to be saturated and contain cholesterol, many American consumers minimize consumption of animal fats, and the price of such fats has declined relative to vegetable oils. At present, there is little prospect of processing technology which will increase the unsaturation of animal fats. Moreover, dietary manipulation of the composition of animal fat by alteration of the animal's diet has not been found practical. Although there is still considerable demand for solid fats in shortenings and spreads, animal fats are not able to compete effectively with vegetable oils because of their content of cholesterol. As a result, a number of schemes have been proposed to remove the cholesterol from animal fats. These methods have included fermentation with cholesterol-degrading bacteria, molecular distillation, deodorization, solvent extraction, extraction with supercritical carbon dioxide, and enzymatic alteration. However, none of these methods has gained widespread acceptance. Most proposed methods do not appear economically feasible.